Earlier this week we showed you Maxto, a similar Windows tool that tiles windows across your desktop via keyboard shortcuts. TwoUp is a similar beast, though it's unfortunately a little lighter on features. Where Maxto allows you to define regions on your screen for more fine-grained control over how large your resized windows are, TwoUp, simply halves your screen vertically and horizontally. By default, pressing Cmd+Opt+Ctrl+Up/Down/Left/Right will move and resize the active window to the corresponding half of your screen (the shortcuts are customizable).